Merge "soc: qcom: spcom: Fix pid management for shared channel" (050ea4ab) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/soc/qcom/spcom.c

+37 −19

Original line number	Diff line number	Diff line
		@@ -176,7 +176,7 @@ struct spcom_channel {
		uint8_t num_clients; /* current number of clients */
		struct mutex shared_sync_lock;

		u32 pid; /* debug only to find user space application */
		u32 pid[SPCOM_MAX_CHANNEL_CLIENTS];

		/* abort flags */
		bool rpmsg_abort;
		@@ -341,7 +341,7 @@ static int spcom_init_channel(struct spcom_channel *ch,
		ch->actual_rx_size = 0;
		ch->is_busy = false;
		ch->txn_id = INITIAL_TXN_ID; /* use non-zero nonce for debug */
		ch->pid = 0;
		memset(ch->pid, 0, sizeof(ch->pid));
		ch->rpmsg_abort = false;
		ch->rpmsg_rx_buf = NULL;
		ch->comm_role_undefined = true;
		@@ -1388,6 +1388,7 @@ static int spcom_device_open(struct inode inode, struct file filp)
		int ret;
		const char *name = file_to_filename(filp);
		u32 pid = current_pid();
		int i = 0;

		pr_debug("open file [%s]\n", name);

		@@ -1425,23 +1426,23 @@ static int spcom_device_open(struct inode inode, struct file filp)
		}
		/* max number of channel clients reached */
		if (ch->is_busy) {
		pr_err("channel [%s] is BUSY and has %d of clients, already in use by pid [%d]\n",
		name, ch->num_clients, ch->pid);
		pr_err("channel [%s] is BUSY and has %d of clients, already in use\n",
		name, ch->num_clients);
		mutex_unlock(&ch->lock);
		return -EBUSY;
		}

		/*
		* if same active client trying to register again, this will fail.
		* Note: in the case of shared channel and SPCOM_MAX_CHANNEL_CLIENTS > 2
		* It possible to register with same pid if you are not the current
		* active client
		* if same client trying to register again, this will fail
		*/
		if (ch->pid == pid) {
		pr_err("client is already registered with channel[%s]\n", name);
		for (i = 0; i < SPCOM_MAX_CHANNEL_CLIENTS; i++) {
		if (ch->pid[i] == pid) {
		pr_err("client with pid [%d] is already registered with channel[%s]\n",
		pid, name);
		mutex_unlock(&ch->lock);
		return -EINVAL;
		}
		}

		if (ch->is_sharable) {
		ch->num_clients++;
		@@ -1449,13 +1450,25 @@ static int spcom_device_open(struct inode inode, struct file filp)
		ch->is_busy = true;
		else
		ch->is_busy = false;
		/* pid array has pid of all the registered client.
		* If we reach here, the is_busy flag check above guarantees
		* that we have atleast one non-zero pid index
		*/
		for (i = 0; i < SPCOM_MAX_CHANNEL_CLIENTS; i++) {
		if (ch->pid[i] == 0) {
		ch->pid[i] = pid;
		break;
		}
		}
		} else {
		ch->num_clients = 1;
		ch->is_busy = true;
		/* Only first index of pid is relevant in case of
		* non-shareable
		*/
		ch->pid[0] = pid;
		}

		/* pid has the last registed client's pid */
		ch->pid = pid;
		mutex_unlock(&ch->lock);

		filp->private_data = ch;
		@@ -1478,6 +1491,7 @@ static int spcom_device_release(struct inode inode, struct file filp)
		struct spcom_channel *ch;
		const char *name = file_to_filename(filp);
		int ret = 0;
		int i = 0;

		if (strcmp(name, "unknown") == 0) {
		pr_err("name is unknown\n");
		@@ -1508,6 +1522,13 @@ static int spcom_device_release(struct inode inode, struct file filp)
		return 0;
		}

		for (i = 0; i < SPCOM_MAX_CHANNEL_CLIENTS; i++) {
		if (ch->pid[i] == current_pid()) {
		ch->pid[i] = 0;
		break;
		}
		}

		if (ch->num_clients > 1) {
		/*
		* Shared client is trying to close channel,
		@@ -1522,14 +1543,11 @@ static int spcom_device_release(struct inode inode, struct file filp)
		}
		ch->num_clients--;
		ch->is_busy = false;
		if (ch->num_clients > 0) {
		mutex_unlock(&ch->lock);
		return 0;
		}
		}

		ch->is_busy = false;
		ch->pid = 0;
		ch->num_clients = 0;
		ch->active_pid = 0;